Hairbrush



FIG. 1 is a top view of a hairbrush showing my new design;

FIG. 2 is a side view thereof;

FIG. 3 is a end view thereof;

FIG. 4 is a side view thereof;

FIG. 5 is an end view thereof; and

FIG. 6 is a bottom view thereof. 

The ornamental design for a hairbrush, as shown. 